XML 113 R96.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Credit Risk (Narrative) (Detail) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2018 USD ($) counterparty | Dec. 31, 2017 USD ($)
Concentration Risk and Guarantor Obligations [Line Items] |  |
Gross credit exposure | $ 61 |
Additional collateral to be posted if the credit related contingent features were triggered | 24 | $ 62
Aggregate fair value of all derivative instruments with credit contingent provisions that are in a liability position | 22 | $ 65
Virginia Electric and Power Company |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Gross credit exposure | 51 |
Wholesale Customers | Dominion Energy Gas Holdings, LLC |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Gross credit exposure | $ 1 |
Credit Concentration Risk |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Number of counterparties | counterparty | 0 |
Amount of exposure for single counterparty | $ 9 |
Credit Concentration Risk | Dominion Energy Gas Holdings, LLC |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Number of counterparties | counterparty | 0 |
Amount of exposure for single counterparty | $ 1 |
Credit Concentration Risk | Wholesale Customers | Sales Revenue, Net | Virginia Electric and Power Company |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Number of counterparties | counterparty | 0 |
Amount of exposure related to sales to wholesale customers for single counterparty | $ 9 |
Credit Concentration Risk | Investment Grade | Investment Grade Counterparty |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Concentration risk, percentage (percentage) | 41.00% |
Credit Concentration Risk | Investment Grade | Investment Grade Counterparty | Virginia Electric and Power Company |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Concentration risk, percentage (percentage) | 48.00% |
Credit Concentration Risk | Investment Grade | Investment Grade Counterparty | Dominion Energy Gas Holdings, LLC |  |
Concentration Risk and Guarantor Obligations [Line Items] |  |
Concentration risk, percentage (percentage) | 2.00% |

X
- Definition Concentration Risk and Guarantor Obligations [Line Items] + References No definition available. + Details
Name: | d_ConcentrationRiskAndGuarantorObligationsLineItems
Namespace Prefix: | d_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Concentration risk, credit risk, financial instrument, maximum exposure for single counterparty. + References No definition available. + Details
Name: | d_ConcentrationRiskCreditRiskFinancialInstrumentMaximumExposureForSingleCounterparty
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Concentration risk, credit risk, maximum exposure for single counterparty. + References No definition available. + Details
Name: | d_ConcentrationRiskCreditRiskMaximumExposureForSingleCounterparty
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of counterparties. + References No definition available. + Details
Name: | d_NumberOfCounterparties
Namespace Prefix: | d_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959 + Details
Name: | us-gaap_AdditionalCollateralAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskCreditRiskFinancialInstrumentMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959 + Details
Name: | us-gaap_DerivativeNetLiabilityPositionAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=d_VirginiaElectricAndPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=d_WholesaleCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=d_DominionEnergyGasHoldingsLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CreditConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=d_InternalAndExternalCreditRatingInvestmentGradeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=d_InvestmentGradeCounterpartyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |